BACKGROUND: The cellular and structural changes that occur during long-term ventricular unloading leading to cardiac recovery are poorly understood. However, we have previously demonstrated that left ventricular assist device (LVAD) support leads to a significant decrease in intracardiac tumor necrosis factor-alpha (TNF-alpha), a protein capable of producing hypertrophy and fibrosis. METHODS: To further define the beneficial effects of long-term ventricular unloading on cardiac function, we determined the effect of mechanical circulatory support on fibrosis and hypertrophy in paired myocardial samples of 18 patients with end-stage cardiomyopathy obtained at the time of LVAD implantation and removal. RESULTS: We determined total collagen as well as collagen I and III by a semiquantitative analysis of positive immune-stained areas in pre- and post-LVAD myocardial samples. We found that total collagen content was reduced by 72% (p < 0.001), whereas collagen I content decreased by 66% (p < 0.001) and collagen III content was reduced by 62% (p < 0.001). Next, we determined myocyte size by direct analysis of cellular dimensions utilizing a computerized edge detection system in pre- and post-LVAD myocardial samples. We found that myocyte size decreased in all patients studied for an average reduction of 26% (33.1 +/- 1.32 to 24.4 +/- 1.64 microm, p < 0.001). CONCLUSION: These data demonstrate that long-term mechanical circulatory support significantly reduces collagen content and decreases myocyte size. We suggest that the reduction of fibrosis and hypertrophy observed may in part contribute to the recovery of cardiac function associated with long-term mechanical circulatory support.
BACKGROUND: The cellular and structural changes that occur during long-term ventricular unloading leading to cardiac recovery are poorly understood. However, we have previously demonstrated that left ventricular assist device (LVAD) support leads to a significant decrease in intracardiac tumor necrosis factor-alpha (TNF-alpha), a protein capable of producing hypertrophy and fibrosis. METHODS: To further define the beneficial effects of long-term ventricular unloading on cardiac function, we determined the effect of mechanical circulatory support on fibrosis and hypertrophy in paired myocardial samples of 18 patients with end-stage cardiomyopathy obtained at the time of LVAD implantation and removal. RESULTS: We determined total collagen as well as collagen I and III by a semiquantitative analysis of positive immune-stained areas in pre- and post-LVAD myocardial samples. We found that total collagen content was reduced by 72% (p < 0.001), whereas collagen I content decreased by 66% (p < 0.001) and collagen III content was reduced by 62% (p < 0.001). Next, we determined myocyte size by direct analysis of cellular dimensions utilizing a computerized edge detection system in pre- and post-LVAD myocardial samples. We found that myocyte size decreased in all patients studied for an average reduction of 26% (33.1 +/- 1.32 to 24.4 +/- 1.64 microm, p < 0.001). CONCLUSION: These data demonstrate that long-term mechanical circulatory support significantly reduces collagen content and decreases myocyte size. We suggest that the reduction of fibrosis and hypertrophy observed may in part contribute to the recovery of cardiac function associated with long-term mechanical circulatory support.
Authors: Konstantinos G Malliaras; John V Terrovitis; Stavros G Drakos; John N Nanas Journal: J Cardiovasc Transl Res Date: 2008-09-30 Impact factor: 4.132
Authors: Marc A Simon; Brian A Primack; Jeffrey Teuteberg; Robert L Kormos; Christian Bermudez; Yoshiya Toyoda; Hemal Shah; John Gorcsan; Dennis M McNamara Journal: J Card Fail Date: 2009-11-14 Impact factor: 5.712
Authors: Veli K Topkara; A Reshad Garan; Barry Fine; Amandine F Godier-Furnémont; Alexander Breskin; Barbara Cagliostro; Melana Yuzefpolskaya; Koji Takeda; Hiroo Takayama; Donna M Mancini; Yoshifumi Naka; Paolo C Colombo Journal: Circ Heart Fail Date: 2016-07 Impact factor: 8.790